RFR: 8323670: A few client tests intermittently throw ConcurrentModificationException

[Andrey Turbanov]

On Mon, 22 Jan 2024 06:50:21 GMT, Tejesh R <tr at openjdk.org> wrote:

>> src/java.desktop/share/classes/javax/swing/plaf/basic/BasicDirectoryModel.java line 417:
>> 
>>> 415:         }
>>> 416: 
>>> 417:         private synchronized <T> boolean compareIterators(Iterator<T> iterator1, Iterator<T> iterator2) {
>> 
>> I'm not sure I understand, how this `synchronized` helps to avoid the issue.
>
> Since concurrent modification exception is thrown, it is clear that the List is being modified while comparing two list. Hence instead of copying the list locally, I have used iterators and comparing element by element in a `synchronized` method which ensures single thread is accessing the iterators. Without `synchronized` I guess it would again cause `concurrentModificationException`.

Vector.iterator and Vector.subList.iterator are still check for modification on iteration (see usages of the method `java.util.AbstractList.SubList#checkForComodification`). It means, if vector was concurrently modified during iteration - iteration will fail with the `ConcurrentModificationException`

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PR Review Comment: https://git.openjdk.org/jdk/pull/17462#discussion_r1461427786